Hybrid vehicles and electric ones are each incorporated with a large battery (main battery) used for driving of the vehicles per se, and use an air-cooling blower to cool the battery. Such the cooling blower is controlled by an instruction received from an electronic control unit (ECU) which controls a wheel driving unit including an engine. The instruction is made regarding cooling capacity (e.g. the rotation number of its fan) of the cooling blower, a cooling period (e.g. a rotation duration time of the fan), and the like.
By the way, the cooling blower has different specifications depending on its destination, which requires different control in accordance with the destination. This requires control software for the ECU which must be changed for each destination. Conventionally, different model numbers have been assigned to the ECUs in accordance with the control software installed in the ECUs even with the same hardware. Before assembling a vehicle, it is confirmed that the model number of the ECU has the correct number different for each destination, and then the ECU with the thus-confirmed model number is assembled. As a result, the number of the ECU model numbers has increased, which requires very complicated management of the model numbers, resulting in a problem of increasing management costs.
To overcome the problem, a method has conventionally been proposed in which a plurality of different pieces of the control software applicable to all of the destinations for in-vehicle electronic equipment is installed in the ECUs with the same model number. When assembling a vehicle, one of the pieces of the control software is used by switching over by using jumper wires, switches, or the like (see Patent Literature 1, for example).
Moreover, as another method for changing the control software, a method has been proposed in which information of the destinations is communicated via a serial communication between the ECU and the electronic equipment (see Patent Literature 2, for example).
However, the conventional methods described above need additional circuit components (CAN transceivers, switches, resistors, etc.) to switch over the control software in accordance with the destination, resulting in increased costs.